Total Maximum Daily Loads Development for Holdens Creek and Tributaries, and Pettit Branch Public Meeting March 26, 2008

Why Are We Here Learn about water quality of these streams Discuss the Total Maximum Daily Load (TMDL) development Gather comments and encourage public participation

The TMDL Process DEQ routinely monitors the quality of waters across the state and publishes a list of impaired waters every 2 years Virginia is required by law to establish a TMDL for each pollutant causing an impairment A TMDL is the amount of a particular pollutant that a stream can receive and still meet Water Quality Standards Recreation Aquatic life Fishing Shellfishing Drinking water Wildlife Designated Uses Water Quality Standards Water Quality Criteria

TMDL=WLA+LA+MOS Where TMDL=Total Maximum Daily Load WLA=Waste Load Allocation (Point Sources) LA=Load Allocation (Nonpoint Sources) MOS=Margin of Safety

Pettit Branch Watershed Fecal Bacteria TMDLs for Holdens Creek and Tributaries, and Pettit Branch Holdens Creek Watershed Virginia Eastern Shore 7-PET000.80 Pettit Branch Watershed

What Are Fecal Coliform, E. coli, and Enterococci? Coliform Bacteria: Common in soil, decaying vegetation, animal feces, and raw surface water Fecal Coliform: Found in the digestive tract of humans and warm blooded animals; Indicator of the potential presence of pathogens in water bodies Enterococci: a type of fecal streptococci; provide a higher correlation than fecal coliform with human pathogens E. coli: Subset of fecal coliform; Correlate better with swimming associated illness http://www.hpa.org.uk/infections/topics_az/enterococci/default.htm

Water Quality Criteria Name Water Type Designated Use Criteria (per 100 ml) Listing Year Holdens Creek (Upper) Class II Transition Recreation Enterococci maximum<104 2006 (Upper+Lower) +Tidal Shellfishing Fecal Coliform 30-month geo. mean<14; 90th percentile<49 1998 Sandy Bottom Br. Class III Nontidal E. Coli maximum<235 Un. Trib. to Sandy Bottom Br. 2004 Pettit Br.

Fecal Coliform Exceedances in Holdens Creek Last 30 Months Criteria Observed Geo. Mean 14 193 90th Percentile 49 435 Station 7-HLD002.67 49/100ml 14/100ml

Enterococci Exceedances in Holdens Creek Criterion Exceedance Maximum<104 76% Station 7-HLD002.67 104/100ml

E. Coli Exceedances in Sandy Bottom Branch Criterion Exceedance Maximum < 235 43% Station 7-SBB000.17 235/100ml

E. Coli Exceedances in Unnamed Tributary to Sandy Bottom Branch Criterion Exceedance Maximum < 235 27% Station 7-XAZ000.30 235/100ml

E. Coli Exceedances in Pettit Branch Criterion Exceedance Maximum < 235 59% Station 7-PET000.80 235 / 100ml

Creek Watershed Land Use Holdens Creek Watershed Land Use

Pettit Branch Watershed Land Use

Potential Bacteria Sources Humans Pets Livestock Wildlife

Potential Source: Human Contribution

Failing Septic Tanks Permitted Source Watershed City Name # of Tanks Person /Tank FC Producing Rate (cfu/d/person) Tank Failing Rate Loads (cfu/d) Holdens Creek 626 2.7 1.95×109 12% 3.96×1011 Pettit Branch 126 7.96×1010 Permitted Source Watershed City Name Permitted Type Holdens Creek Temperanceville Tyson Farms, Inc VPDES

Potential Sources: Wildlife, Livestock, and Pet Pettit Branch Holdens Creek Dogs 29 287 Livestock Cattle 3 17 Swine 6 44 Chickens 24,926 176,680 Horses 1 4 Sheep Wildlife Ducks 39 340 Geese 253 Deer 32 309 Raccoons 37 385

Bacteria Source Tracking (BST) Data Will Be Available by the End of March Uses Antibiotic Resistance Analysis for source load allocation into 4 categories Human Pets Livestock Wildlife

Un. Trib. to Sandy Bottom Br. TMDL End Point Name Water Type Designated Use Criteria (per 100 ml) Holdens Creek (Upper) Class II Transition Recreation Enterococci maximum<104 (Upper+Lower) +Tidal Shellfishing Fecal Coliform 30-month geo. mean<14; 90th percentile<49 Sandy Bottom Br. Class III Nontidal E. Coli maximum<235 Un. Trib. to Sandy Bottom Br. Pettit Br.

Holdens Creek Enterococci TMDL: Recreational Use DEQ translator: convert the enterococci criterion of 104 counts/100 ml to fecal coliform equivalent criterion Fecal coliform = 551 counts/100 ml One order of magnitude higher than the shellfish criterion The former will be met simultaneously as the latter is attained

Modeling Approach Reduction (%) Flow Observations (concentration) Temperature (decay) Model prediction Model Compare to observations (calibration) Adjust Loading Results are good (statistics) Loading Existing Loads Reduction (%) TMDL Compare to Criteria Results are good Adjust Loading Loading Water Quality Criteria Model prediction Model Temperature (decay) Flow

Modeling Approach: Linking Sources to Water Quality Sandy Bottom Branch, Unnamed Tributary to Sandy Bottom Branch, and Pettit Branch Input Observed bacteria concentration or water quality criterion Bacteria decay rate Simulated flow information Stream cross-sectional area Distributed-Source Model No tidal influence The watershed associated with the head water is small Assume the bacteria are discharged laterally into the stream and fully mixed laterally and vertically Using Bayesian method to handle uncertainties Output Existing bacteria load and loading capacity (TMDL) under different flow regimes

Tidally Averaged Transport Model Holdens Creek Input Observed bacteria concentration or water quality criterion Bacteria decay rate Simulated flow information Stream cross-sectional area Tidally Averaged Transport Model Tidal influence Applies to long and narrow estuaries Assume the bacteria are discharged laterally into the stream and fully mixed laterally and vertically Using Bayesian method to handle uncertainties Output Existing bacteria load and loading capacity (TMDL)

Model results of Holdens Creek

Reduction Simulation (Sandy Bottom Branch and Unnamed Tributary)

Loading Allocations Non-point Source: To be determined using BST data Point Source (if present in watershed): Based on permit limits and discharge monitoring reports Use existing maximum loading discharged to the stream

Summary of the TMDLs Sandy Bottom Branch and Unnamed Tributary to Sandy Bottom Branch E. Coli TMDL Recreational Use Flow Interval I Flow >70% II 70% <Flow <30% III Flow<30% Flow (cfs) 0.46 1.77 5.62 TMDL (Count/Day) 3.46E+09 1.23E+10 3.84E+10 WLA (Count/Day) 1.65E+09 LA (Count/Day) 1.81E+09 1.06E+10 3.67E+10 MOS Implicit

Holdens Creek Fecal Coliform TMDL: Shellfish Growing Water Use Category Criterion (MPN/100ml) Existing Load (Counts/day) Allowable Load Required Reduction Geometric Mean 14 1.58E+12 3.34E+12 78.85% 90th Percentile 49 7.59E+13 7.09E+12 90.66% Category TMDL (Counts/day) WLA LA MOS Geometric Mean 3.34E+12 na Implicit 90th Percentile 7.09E+12

Pettit Branch

Pettit Branch TMDL

Continue Work Conduct load allocations using BST data Respond to comments Finalize TMDL reports

Questions?